Unity Lifecycle & Execution Order -- Correctness Patterns

Prerequisite skills: unity-scripting (MonoBehaviour lifecycle, coroutines), unity-foundations (GameObjects, components)

These patterns target initialization bugs, null reference exceptions from destruction timing, and subtle editor-vs-runtime differences that cause "works in editor, fails in build" issues.

PATTERN: Fake-Null Trap (?. and ?? on Destroyed Objects)

WHEN: Null-checking Unity objects that may have been destroyed

WRONG (Claude default):

// C# null-conditional and null-coalescing bypass Unity's == override
myComponent?.DoSomething();          // May call method on destroyed object!
var fallback = myComponent ?? other; // May return a destroyed "fake-null" object!